Is anyone using one of these? Schumacher SC1455 Level 1 and Level 2 Portable EV Charger
You might look at the Schumacher as well. It's cable is quite a bit longer which might be useful on the road. https://www.amazon.com/Schumacher-Portable-EV-Charger-Batteries/dp/B08PQ42SJ4/
You'd need a 6-20 to 10-30 adapter, but you can use that without issue with this evse.
Like this one? Seems like it could be acceptable as a spare/backup EVSE...
https://www.amazon.com/Schumacher-Portable-EV-Charger-Batteries/dp/B08PQ42SJ4
I have a Level 1/2 that looks just like yours but under the Schumacher brand. Worked right out of the box, plugged it in to the wall and car and she says "Charging Started". Works so well for me I bought another to keep in the car but saved over $50 by buying a returned unit via Amazon Warehouse. It looked just like new and was zipped or re-zipped back into the box. My Schumacher EVSE has a blue light that blinks when charging and is steady when not.
https://www.amazon.com/dp/B08PQ42SJ4?psc=1&ref=ppx_yo2ov_dt_b_product_details
My only comment why it's not working is if there is a charging schedule in place setup in the car which can be overridden by pressing the schedule override button in the charge port. It's the lower button that printed with ZZZ symbols and "HOLD".
Just for the heck of it. Set it up for charging and if nothing happens, press that schedule override button and hope she says "Charging Started".
Nema 6-20 is pretty light duty, so it won't do a really fast charge. I have one but it's just for a PHEV, an EV would have a much larger battery. If you don't drive that far it would be ok, like 75 miles a day or less would charge in under 6 hours. A full 20 to 80% on say a 64KW battery would take closer to 12-15 hours.
I have this one and have had no problems with it. I actually got it open box on amazon for $50 off, someone likely bought it and it had the wrong kind of plug so it was returned.